CountQuery 최적화

1. CountQuery 최적화

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• PageableExecutionUtils.getPage(content, pageable, () -> ~.fetchCount())
• CountQuery를 날릴려면 fetchCount()가 호출 되어야 함.
• PageableExecutionTuils.getPage()를 통해 count 쿼리가 생략 가능한 경우는 Countquery 생략
  • 페이지 시작이면서 컨텐츠 사이즈가 페이지 사이즈보다 작을 때
  • 마지막 페이지 일 때 (offset + 컨텐츠 사이즈를 더해서 전체 사이즈 구함)

    @Override
    public Page<MemberTeamDto> searchPageComplex(MemberSearchCondition condition, Pageable pageable) {

       //content를 바로 가져오고.
        List<MemberTeamDto> content = queryFactory
                .select(new QMemberTeamDto(
                        member.id.as("memberId"),
                        member.username,
                        member.age,
                        team.id.as("teamId"),
                        team.name.as("teamName")))
                .from(member)
                .leftJoin(member.team, team)
                .where(
                        usernameEq(condition.getUsername()),
                        teamNameEq(condition.getTeamName()),
                        ageGoe(condition.getAgeGoe()),
                        ageLoe(condition.getAgeLoe()))
                .offset(pageable.getOffset())
                .limit(pageable.getPageSize()) //페이지 당 몇 개?
                .fetch();

        //count쿼리는 직접 날림.
        JPAQuery<Member> countQuery = queryFactory
                .select(member)
                .from(member)
                .leftJoin(member.team, team)
                .where(
                        usernameEq(condition.getUsername()),
                        teamNameEq(condition.getTeamName()),
                        ageGoe(condition.getAgeGoe()),
                        ageLoe(condition.getAgeLoe()));

        return PageableExecutionUtils.getPage(content, pageable, () -> countQuery.fetchCount() );
        // return new PageImpl<>(content, pageable, total);
    }

 

2. GitHub : 210905 CountQuery

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GitHub - bsh6463/Querydsl